concealment writes with news that a court battle has brought to light details on how the FBI's "stingray" surveillance tool works, and how they used it with Verizon's help to collect evidence about an alleged identity thief. Quoting: "Air cards are devices that plug into a computer and use the wireless cellular networks of phone providers to connect the computer to the internet. The devices are not phones and therefore don’t have the ability to receive incoming calls, but in this case Rigmaiden asserts that Verizon reconfigured his air card to respond to surreptitious voice calls from a landline controlled by the FBI. The FBI calls, which contacted the air card silently in the background, operated as pings to force the air card into revealing its location. In order to do this, Verizon reprogrammed the device so that when an incoming voice call arrived, the card would disconnect from any legitimate cell tower to which it was already connected, and send real-time cell-site location data to Verizon, which forwarded the data to the FBI. This allowed the FBI to position its stingray in the neighborhood where Rigmaiden resided. The stingray then "broadcast a very strong signal" to force the air card into connecting to it, instead of reconnecting to a legitimate cell tower, so that agents could then triangulate signals coming from the air card and zoom-in on Rigmaiden’s location. To make sure the air card connected to the FBI’s simulator, Rigmaiden says that Verizon altered his air card’s Preferred Roaming List so that it would accept the FBI’s stingray as a legitimate cell site and not a rogue site, and also changed a data table on the air card designating the priority of cell sites so that the FBI’s fake site was at the top of the list."